Fluid flow control apparatus



Feb. 10, 1953 M. H. GROVE ET AL 2,627,870

FLUID FLOW CONTROL APPARATUS Flled April 2, 1945 2 SHEETSSHEET' 1 INVENTOR. M b. r'm e BY AIME/344x27."

ATTORNEY Feb. 10, 1953 M. H. GROVE ET AL 2,627,87

FLUID FLOW CONTROL APPARATUS Flled April 2, 1945 2 SHEETSSHEET 2 FIE| E ATTORNEY Patented Feb. 10, 1953 UNITED STATES PATENT OFFICE FLUID FLOW CONTROL APPARATUS Marvin H. Grove, Piedmont, and Austin U. Bryant, Berkeley, Calif., assignors, by mesne assignments, to Grove Regulator Company, a corporation of California Application April 2, 1945, Serial No. 586,136

ducing regulator, at a time when no gas is being I consumed from the low pressure side, may cause a building up of an unsafe pressure in the low pressure piping. The conventional way to provide such protection is to connect a pop 01f or pressure relief valve to the low pressure side of the regulator whereby when the pressure rises beyond a predetermined value gas is vented to the atmosphere. Conventional relief valves of this type make use of a diaphragm loaded by means of a compression spring.

Conventional apparatus as described above is not entirely satisfactory due to inherent defects and difficulties of adjustment. For example when it is desired to adjust the pressure reducing regulator for different outlet pressures, it is necessary to make corresponding adjustments of the pressure relief valve. This not only requires double manipulation of the two devices but in addition it is diflicult to set the relief valve for venting fluid at a desired pressure above normal outlet pressure, without deliberately building up the outlet pressure to an abnormal value until the relief valve is operated. Also the loading springs used are subject to variations so that one cannot rely upon the point of opening remaining constant over a period of time.

It is an object of the present invention to provide a novel fluid flow control apparatus incorporating in combination a pressure reducing and a pressure relief valve, and with simplified commcn loading for both devices.

Another object of the invention is to provide apparatus of the above character which can be more readily adjusted in practice and which is more reliable in protecting the low pressure system.

Additional objects of the invention will appear from the following description in which the preferred embodiment has been set forth in detail in conjunction with the accompanying drawing.

Referring to the drawing:

present invention.

Figure 2 is a cross-sectional detail showing the construction of the pressure relief device and taken along the line 22 of Figure 3.

Figure 3 is a cross-sectional detail taken along the line 33 of Figure 2.

Figure 4 is an enlarged cross-sectional detail showing the construction of the valve means and associated parts.

Figure 5 is a further enlarged detail showin the construction of the valve means.

The apparatus of the drawing consists generally of a pressure-reducing regulator l0, and a pressure relief valve.

receive air or other gas under pressure to load the same, and this air is supplied from a common source.

The pressure reducing regulator illustrated embodies principles of the invention disclosed and claimed in Grove Patent No. 2047,101. Thus the device in this instance consists of a body I2 provided with the inlet and outlet passages I3 and M, which connect with the piping l6 and I1. Pipe 16 connects with a source of gas or fluid under pressure, While pipe I! forms a part of the low pressure system from which gas is to be consumed. Pressure relief valve II also includes a body [8 having a passage [9 for connection with pipe l1, and a passage 2| through which gas is 1 vented to the atmosphere or to a point of relatively low pressure. The passage I9 is connected to both pipe I! and to pipe Ila which leads to the point of demand.

The pressure reducing regulator includes a flex- V ible diaphragm 22 having its peripheral edge portion clamped between the annular surfaces 23 and 26, the latter being formed respectively on the dome part 26, and the body l2. The dome upon the diaphragm 22. Plate 21 in conjunction.

with orifice 28 provide a restriction against abrupt movements of the diaphragm in order to prevent chattering. The lower side of the diaphragm is engaged by the dia hragm plate 3!, which in turn engages one end of the slidablethrust rod 32. A light compression spring 33 is shown for urging the diaphragm plate against v the diaphragm.

The lower portion of rod 32 terminates adja- 1 cent a valve seat ring 34, which in turn is mounted within the valve body. The periphery As will be presently explained both of these devices are adapted to q of the seat ring is shown sealed against leakage by suitable means such as the resilient O ring 3%. A circular screen 31 is shown disposed below the seat ring in order to screen out solid particles from fluid passing through the seat ring orifice 38. A conicalseat 39ai iormedn the seat ring 34 and is-engagedby the conical faced. valve member 4|. The valve member is formed upon one end of a cylindrical member 42, which in turn is slidably fitted within the bore 43,and,is urged by compression spring 44 towardclosed position of the valve member. diaphragm 22 is in free communicationwvith the outlet passage [4, and therefore oneside-ofrthe diaphragm is subjected to outlet pressure, whereas the other side is subjected-to the pressure of gas within the dome chamber 29.

Assuming a definite loading pressure within the chamber 29, the regulator described above will automatically supply I as. or fluid to I the outlet passage; 141 at a;v pressure somewhat below the:

loading pressure ,tdepending upon theproportioneingiofithe ,valveseat 3.8: For. example in atypical instance Where it is desired-to-maintainan outlet pressureofabout 100* pounds,- the corresponding. loading inthe: chamber 29 may be '110 pounds. The pressure upon the inlet sideimay vary'over arwide rangeas for example from say 150 pounds to: several: thousand pounds; outlet pressure maintained may vary slightly withavaria tionson .thevinlet side; but in no event willi. this: pressure equal i or exceed the loading pressure:-

The pressurezreliefvalvezll in this instanceincludesfa-flexible fluidr'operated-diaphragm 46, the central portion of which is shown reinforced-by the imbeddedtmet'al'discAlZ The flexible peripheral marginrof thisdiaphragm'is shown clamped between annular surfaces 48 iandl49 formed respectively on=thedome orreover part 51, and the body I 8.1 Within. the body there is: an annular seat 52 engaged {by 'theiadjacentsidezof the diaphragm when the valve is: closed. A chamber-53 extends beneath that part'of the diaphragm sur rounding the-seat 52; and this chamber is-infree communication withthe passage: IS: The other side-of "the diaphragm is exposed to gaspressure in the chamber 54=formed by' the-dome or. cover part The areaofi the diaphragm exposed'to a gas in chamber -53is substantially lessthanthe area exposed to chamberbti Therefore fora given gas pressure in chamberid a considerably higher pressure musttbe applied 5 in chamber? 53 to force the diaphragm ofi'it seat tothereby permit free venting of gas to the atmosphere.

The chamber 5401'; the dome 5'! is directly connected to the chamber: 29 of "the pressure reducing regulator; as by means of a connecting pipe or-tub'e 56. Thus the pressurewithin' chambers 29 and Mare substantially em al at all times.

It is possible to-trap loading'gas within the chambers29'and '54 in order to maintain a desired loading. However itis preferable to use a small capacity loading regulator for this purpose, whereby an operator may readily increase or lowerthe loading pressure by a simple adjustment. A small loading regulator of the type disclosed in Patent No. 2,342,659 is satisfactory for thispurpose.

A loading regulator 58 of novel construction is illustrated'inthe drawing and i mounted directly upon the body l2 of the main regulator; The" closure'plug59 which is threaded into body 12"forms in efiect the body of the loading regulator: Suitable means such as the resilient O ring The space 451 below the 6| prevents leakage between the plug and body I2. The plug or body 59 is bored and threaded to receive the plug 62, which is formed with bores 63 and 64 extending into its opposite ends. A stationary valve seat 66 is formed between the bores -63,and 64430 thereby providea connecting valvaoriiice...v Cooperating with and extending through the seat 66 there is a small valve member: designated generally at 61, which is formed on one end (lower end as illustrated) of the valve carrying member -68. The upper end of the valve carrying member 68.,isguided Within the bor 69, and. aacompressionspring H serves to urge membertdatowardtheseat 66. Port 12 serves to establish free communication between bores 43 and 69, so that by virtue of clearance about member 42 of'the main pressure reducing regulator, the spaces! 0; immediately above the seat 66 is in communication with the inlet passage l3.

Belowthe seat fifithere is.-a.thrust.smember;13. the'uppcr. end ofwhich is. provided with a -.seat- 74. through which. the duct 15 communicates. Member 13 extends, through the. flexiblediaphragm Tl, and through thediaphragmiplateilii underlying the diaphragm. Its lower end is threaded to receive theclamping cap. 79, which has a passage iificommunicating with passage 161 and with the space on the .lower sideoftliediae phragm ll, the latter beinginfreeicommunicae tion with the atmosphere throughtheportflli The peripheral edge portion of the diaphragml H i gripped between thering 82; and anannm lar surface formedon the/lower end of the body 58. A suitable gasket-,flacan.be provided. to prevent leakage: Ring--82risheld against the body, by a casing 8 l-which has athreaded attachment- 86 with the body, and-Whichhas a shouldenii] engaging thering 82-.

A coiledv compression spring 88 is; disposed; within the. casingtandserves. to load (the dia--- phragm 11. One end of this spring is' seated upon: the disc, 89-, which in turn is-seated upon the rounded endofcap- 19; The-other endof-the compression spring is seated upon disc 9!, which is engaged by the innerend :of: a'set :screw- 92 Y whereby thetension of. thespring canxbe-ad justed.

The space 93above-the diaphragm-ll isshown. connected by pipe Sid-toafitting 96 on-the'dome 26 of the main regulator. Thus the outlet orlow' pressure side of the-loading regulator -58'is con-- nectedto the chambers 29*and54 of the main loading regulator andirelief valve.

The small valve member 67 is: provided with two: valve surfaces seand M which cooperate: respectively with the seatstt andl l. When valve surface 86 is in engagementwith seat 6B-.-valvesurface 91 likewise'engages seat. M; andtherefore-at this time'there can be no flow of gas through the loading regulator. Assuming that pressure on the outlet side (i. e. space 93) drops below a given value th 'pressure'on-th'euppersi-de ofxdiaphragmll is lowered tosuch a point that springv 88- forces member- 13' upwardly: Such upward movementunseats valve surface flfi withrespect to'seat 86; thus permitting gas from the inflow side to pass through seat"66,'. past member 13; to the outlet space 93, and thence through pipe l to the chambers 29 and 54. When the outlet pressurehas been restored to the desired'value the valve'surface QB' again engages and closes upon-th seat 665 If thepressure in chamberszsand 56 should increase beyond the value'desired, as'for'example due to an increase in temperature, diaphragm- Fl-is flexed downwardly to unseat valve surface 91 which respect to seat 14, thus permitting gas from space 93 to pass through ducts l6 and 8] and vent to the atmosphere. When sufficient venting has taken place to restore the desired pressure, then valve surface 91 again closes upon seat 14.

Operation of the complete apparatus described above can be reviewed as follows: Loading regulator 58 is set to produce a desired outflow pressure from the main pressure reducing regulator It. This can be checked in practice by use of a pressure gauge connected to piping H or Ila. This loading remains the same irrespective of use of gas in the low pressure system. If there should be a complete shut off of gas consumption and the pressure reducing regulator should not shut off with absolute tightness, then there may be a gradual rise in pressure on the outlet side until such pressure rises to an unsafe value above the normal regulated pressure. Before such rise in pressure on the outlet side has become dangerously excessive, diaphragm 46 is forced upwardly against the pressure of gas in chamber 54 to open the same with respect to the seat 52, thus permitting venting of gas through passage 21 to the atmosphere. When the pressure has been restored to a, lower safe value by such venting, diaphragm 46 is automatically restored to closed position. As an example of pressure values which can be used in an actual installation, the pressure reducing regulator can be adjusted to deliver say 100 p. s. i. to the piping 1?, Hg, with a loading pressure in chamber 29 of 110 p. s. i. The same pressure of 110 p. s. i. will be applied to diaphragm 46 in the chamber 54. The ratio between the area exposed to gas in chamber '54, and the area exposed to fluid in passage 19, can be such that diaphragm 46 is forced to open position when the pressure in passage 19 increases to a value of say 120 p. s. 1. Assuming now that the loading regulator 58 is adjusted so that the pressure reducing regulator delivers a regulated pressure of say 75 p. s. i., the loading of the pressure relief valve I I is likewise altered whereby a comparable margin over 75 p. s. i. is provided before the relief valve automatically opens.

Aside from the advantages of automatic adjustment for both pressure reducing and relief valves, the invention totally eliminates loading springs, with the exception of the relatively small loading spring in the loading regulator.

We claim:

1. In fluid flow control apparatus, a pressure reducing regulator having an inlet adapted for connection with a source of fluid under pressure and an outlet adapted for connection with a low pressur system, said pressure reducing regulator having a fluid operated diaphragm and means forming a space on one side of the diaphragm adapted to receive gas under pressure to load the diaphragm, the regulator serving to maintain an outlet pressure slightly less than the gas loading pressure, a pressure relief valve having an inlet connected to the outlet side of the pressure reducing regulator, said pressure relief valve including a fluid pressure operated diaphragm and means forming a space on one side of the diaphragm adapted to receive gas under pressure to load the same, said pressure relief valve being adapted to vent gas from the outlet and thus relieve pressure responsive to an outlet pressure in excess of the loading pressure upon the last named diaphragm, said spaces being in free intercommunication whereby the loading gas pressures upon said diaphragms are the same at all times, and means enabling an increase or a decreas in gas loading pressure whereby the settings of both said pressure reducing regulator and said pressure relief valve are altered simultaneously.

2. Apparatus as in claim 1 in which said last means comprises an adjustable loading regulator having its inlet connected to the inlet side of the pressure reducing regulator and its outlet connected to said chambers.

MARVIN H. GROVE. AUSTIN U. BRYANT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,805,702 Mastenbrook May 19, 1931 1,861,506 Nelson June 7, 1932 2,181,428 Grove Nov. 28, 1939 2,270,304 Jacobsson Jan. 20, 1942 2,342,659 Grove Feb. 29, 1944 2,357,318 Donaldson Sept. 5, 1944 

